Culture

Best grown in deep, fertile, medium moisture, well-drained soil in full sun to part shade. Tolerant of summer heat. Add compost as needed before planting. Larger shrubs appreciate some shelter from strong winds. Unlike herbaceous peonies, the stems of tree peonies (which are woody shrubs) do not die to the ground in winter and should not be cut back after frost. No pruning is required, except to cut out dead wood or suckers in early spring. If plants become leggy, a moderate pruning in early fall can be done to shape plant and encourage additional growth on the lower part of the plant. Remove spent flowers after bloom. These long-lived plants usually take several years to establish, and are best left undisturbed once planted. Moreover, plant roots go deep and transplanting can be difficult. Appreciates some winter protection in USDA Zone 4 and the colder areas of Zone 5.

Noteworthy Characteristics

Paeonia suffruticosa, commonly called tree peony, is a deciduous, woody shrub that typically grows 3-5' tall with a 4' spread. The true species features large flowers (6-8" across) with pink to white petals, each petal having a purple basal patch. Many cultivars of this species have been developed, with a wide range of petal colors including red, pink, purple, white and yellow. Cultivar flower forms range from single to semi-double to double. Blooms in early spring (May in the St. Louis area). Medium green foliage is deeply divided into oval to lance-shaped leaflets and remains attractive throughout the growing season.

Genus name comes from the Greek name for Paeon, physician of the gods and reputed discoverer of the medicinal properties of plants in this genus.

Problems

Tree peonies are considered to be relatively pest free. Some susceptibility to canker, leaf blight, stem wilt and scale. Ants on peony buds are common and totally harmless.

Garden Uses

Excellent in borders as specimens or in groups. Also effective as accents or hedges along fences, sidewalks, driveways or walls. Flowers are extremely showy, and foliage remains attractive throughout the growing season, either alone or as a frame or backdrop for other flowering plants.